This invention relates to contacting devices in general and more particularly to an improved contacting device for connecting the end of an electrical wire, in which an elastic element fastens the wire end mechanically to a contact element and ensures sufficient contact pressure between the wire and the end of contact element.
Contacting devices of this general nature are commercially available in the form of a clamped connection which is known as a Termi Point Connection. Such is described in the book "Industrieelektronik" (Industrial Electronics) by D. Ernst and D. Strole, Springer Verlay, Berlin Heidelberg/New York, 1973, page 101. In a clamped connection of this type, a clamp, in the form of an elastically deformed element, pushes a stripped wire end of a solid or stranded conductor against a contact element in the form of a contact pin. The clamp grips both wire end and the contact pin.
Such clamped connections are made utilizing a manually or pneumatically operated wiring tool. Because of the first forces which occur during clamping, a deformation of the wire end and the clamp occurs and thereby a reliable and gastight pressure connection is made. It is possible to place up to three such clamped connections on one contact pin, one behind the other. Clamped connections of this nature are used for wiring of terminal boards. Terminal boards of this nature are found for example on the rear of a modular chassis and are utilized for the functional interconnection of various modules, e.g., subassemblies, mounted on the front side of the chassis.
The disadvantages of this contact device are that a complicated and expensive wiring tool is necessary for connecting the wire ends, and it is not easy to make changes should errors in wiring occur. This problem with making changes is particularly severe where two or three connections are made on a contact pin one behind the other. In that case the outer connection which has been clamped must be bent up with a suitable tool to make available the inner clamp. Reestablishing the connection which has been changed again requires the use of a special wiring tool. Furthermore, with a contacting device of this nature, it is particularly important that the size of the cross section of the wire be carefully matched to the end dimension of the contact device.
Another type of connection is a wire-wrap connection. In making such connections solid conductors are wrapped several times around a pin shaped contact element using a complicated wrapping tool. In such a connection because of the sharp corners of the contacting element, the element itself and the solid conductor are notched and as a result any poorly conducting surface layers are pierced. In such a technique it is also possible to make several wrapped connections on a single contact element one behind the other. The disadvantages of this technique are, as with the clamped connections, that a complicated wrapping tool is needed and that it is not easy to make changes. Furthermore, wires with special insulation are required.
In view of these difficulties the need for an improved contacting device of the general type mentioned above on which several wires of different cross sections and different nature can be connected without the need for expensive, complicated wiring tools and which permits easily making changes is evident.